Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 12 of 12 for “"mackinawite"”.
-
The Chemodenitrification of Nitrate by Green Rust and Mackinawite and its Geochemical Implications
… aspects around NO3- chemodenitrification by mackinawite (FeS). Although it was observed that NO3- chemodenitrification kinetics were faster at acid pH values, in disagreement with thermodynamics, this observation most likely resulted from the higher reactivity of a soluble reductant or …
-
Ripening Kinetics of Iron Sulfides in the Presence/Absence of a Carbonyl Group
The ripening of mackinawite (Fe₁+ₓS) to pyrite (FeS₂) or greigite (Fe²⁺Fe³⁺ ₂S₄) was examined at temperatures between 23 and 90°C to better understand the kinetics of low temperature iron sulfide crystallization in the presence or absence of aldehydes. Mackinawite starting material was synthesized …
-
Interaction between ferric hydroxides and dissolved sulfide in anoxic aquifers: Pathway and kinetics of iron and sulfur products formation
… could not be recovered as stoichiometric FeS (or mackinawite), which is consistent with previous studies (“excess Fe(II)”) (Hellige et al., 2012; Poulton, 2003; Poulton et al., 2004). The formation of the “excess Fe(II)” seems compete with the formation of FeS/mackinawite. The excess Fe(II) …
-
Estudo da permeação de hidrogênio e fragilização pelo hidrogênio de um aço API 5L X80
… due to a conjoint formation of pyrrhotite and mackinawite. The FeS film as mackinawite presented to be the most efficient as a barrier to hydrogen uptake and stress resistance, resulting in lower current densities of hydrogen permeation and lower levels of embrittlement in the 10-2M solution.
-
Ore mineralogy and paragenesis of a portion of the Great Gossan Lead district, Virginia
… phases--galena, arsenopyrite, pyrite, cubanite, mackinawite, tetrahedrite, stannite, and native bismuth--are disseminated throughout the ores. Pyrite is locally common as corroded primary euhedrae in some are bodies. Sphalerite occurs as disseminated anhedral aggregates commonly containing …
-
Microbially influenced corrosion in sour environments
… mainly of monosulfides, implying the presence of mackinawite or pyrrhotite. By using electrochemical polarization experiments, it was found that calcium alginate enhanced the rate of corrosion; agarose reduced the rate of corrosion. This is in contrast to previously published literature. Contrary …
-
Investigating Bisulfide Sorption onto Bentonite through Laboratory Experiments and Numerical Modelling
… precipitation as iron sulfide, FeS (likely mackinawite), and (iii) surface complexation reactions with surface hydroxyl group (OH) at the edge sites of montmorillonite. The model successfully described the experimental trends and provided valuable insights into the relative contribution of …
-
Modeling of mechanisms affecting the growth and breakdown of iron sulfide films
… of failure in the layered iron sulfide phase, mackinawite. We identify through computational stress-strain curves that cathodically generated H2 molecules are detrimental to the mechanical stability of the mackinawite phase and cause localized degradation of the passive film and act as a …
-
A methodology for studying denitrification by recently formed sulfides
… hydrogen sulfide (H2S), iron monosulfide (FeS), mackinawite (FeS), and greigite (Fe3S4). The objective of this research was to design and begin implementing a methodology for investigating the effects of recently formed sulfides on denitrification. </p><p> In order to begin investigating the …
-
TIMELESS QUESTIONS AND MODERN CHALLENGES: A JOURNEY FROM THE ORIGIN OF LIFE IN HYDROTHERMAL VENTS TO ELECTROCHEMICAL CO2 REDUCTION
… pH conditions. First, two model materials, Mackinawite [FeSm] and Violarite [(Fe,Ni)3S4] have been prepared by homogeneous precipitation method, obtaining the materials in powder form. The samples have been widely characterized in terms of crystalline structure, particle dimensions, …
-
Schwefelhaltige Arsenspezies in Grundwässern
… Schwefelsubstituent in das Kristallgitter von Mackinawite bzw. Pyrit (FeS, FeS2) festgelegt. Die ermittelten Prozesse können ggf. zur Sanierung bzw. Sicherung von Standorten mit arsenhaltigen Rückständen im Boden bzw. von arsenbelasteten Grundwässern eingesetzt werden. Dabei ist auch von …
-
Sulfide immobilization with taconite tailings: products, capacity, and stability
Excess sulfate (SO42-) may negatively impact certain freshwater ecosystems. In Minnesota, wild rice (zizania palustris) is threatened by excess sulfate. Several technologies are being researched and developed to remove sulfate from waters where wild rice grows. One of which is a two-part active …